1989 Mustang 5.0L drive line vibration?

possibly driveshaft out of balance or u-joints need replacing....

also it could be a tire/wheel balance issue......

+1 on the u joints. when does the vibration start? what speed? and in gear or in neutral, both? also make sure the 4 bolt that hold the driveline up in the rear arent loose.

Mine did the same thing and i got a ford racing aluminum d/s. The used car dealer got the worst of it though. He bought me new tires to try and fix it. I needed new tires anyways lol. Its been 7 years now and I have a new vibration. I have het to look at it since I dont drive it much anyway.

+1 on tightening the 4 bolts holding up the drive shaft. I had the same problem. I bought an aluminum ds and when I installed it, I noticed the 3 remaining bolts were all loose. Lol,boy was I embarrassed! :rollgrin:

checked the bolts they were tight ujoints are good no play in them but there is play in the slip yoke at the trans

it is from 55mph to ? i peged the spedo on the reset button dont know how fast that is on a 85mph spedo
vibrates when you let off the gas not when geting on it though

Driveshaft is out of balance

U-Joints too......